Torque tools for stepping up or stepping down applied torque are known and essentially comprise a torque input and a torque output between which is interposed a gear train to step up or step down the output torque. Generally, a motor provides torque input to the torque tool and the output torque is applied to an object to be torqued by means of a chuck or other suitable connector. One problem associated with such torque tools is to limit the output torque to a preselected level. Prior devices for limiting torque output are well known as exemplified by, e.g., U.S. Pat. No. 2,152,517; 3,515,251; and 3,613,853. However, one problem which is not always satisfactorily overcome by prior devices is that of applying the torque uniformly and smoothly with minimum impact forces being applied to the object or member being torqued.
It is accordingly an object of the present invention to provide a novel torque tool which overcomes the foregoing problems and which permits smooth application of torque to a member or object by means of a device in which the torque output level is limited to a preselected value.
It is another object of the present invention to provide a torque tool which feeds back reactive torque to actuate a braking means which controls the torque output from the tool.
It is another object of the present invention to provide a pneumatic motor operated torque tool and one in which the level of reactive torque required to apply the braking means to the torque transmission shaft can be selected by simple adjustments of the tool.
Other advantages and objects of the invention will be apparent from the following description.